A stacked transformer core is comprised of thin metallic laminate plates, such as grain oriented silicon steel. This type of material is used because the grain of the steel may be groomed in certain directions to reduce the magnetic field loss. The plates are stacked on top of each other to form a plurality of layers. A stacked core is typically rectangular in shape and can have a rectangular or cruciform cross-section. A cruciform cross-section increases the strength of a stacked core. In addition, a core leg having a cruciform cross-section provides more surface area for supporting a coil. An example of a conventional stacked transformer core having a cruciform cross-section is shown in U.S. Pat. No. 4,283,842 to DeLaurentis et al. The core of the DeLaurentis et al. patent has upper and lower yokes with cruciform cross-sections, as well as legs with cruciform cross-sections.
Although a stacked core having a cruciform cross-section, such as the core of the DeLaurentis et al. patent, provides additional support and strength, such a core is typically more difficult to manufacture and results in more wasted steel. Therefore, it would be desirable to provide a stacked transformer core that has the benefits of a cruciform cross-section, but is simpler to manufacture and reduces the amount of steel that is wasted. The present invention is directed to such a transformer core and a method of making the same.